title: Composite polymer electrolytes for fuel cell applications: filler-induced effect on water sorption and transport properties.
abstract: Nafion- and sulfonated polysulfone (SPS)- based composite membranes were prepared by incorporation of SnO2 nanoparticles in a wide range of loading (0${ \div }$35 wt. %). The composites were investigated by differential scanning calorimetry, dynamic vapor sorption and electrochemical impedance spectroscopy to study the filler effect on water sorption, water mobility, and proton conductivity. A detrimental effect of the filler was observed on water mobility and proton conductivity of Nafion-based membranes. An increase in water mobility and proton conductivity was instead observed in SPS-based samples, particularly at low hydration degree. Analysis of the water sorption isotherms and states of water revealed that the presence of SnO2 in SPS enhances interconnectivity of hydrophilic domains, while not affecting the Nafion microstructure. These results enable the design of suitable electrolyte materials that operate in proton exchange membrane fuel cell conditions.
authors.affiliation: Department of Chemical Science and Technology & NAST Center, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133 Rome (Italy). barbara.mecheri@uniroma2.it.
authors.forename: Barbara
authors.initials: B
authors.lastname: Mecheri
authors.forename: Valeria
authors.initials: V
authors.lastname: Felice
authors.forename: Alessandra
authors.initials: A
authors.lastname: D'Epifanio
authors.forename: Ana C
authors.initials: AC
authors.lastname: Tavares
authors.forename: Silvia
authors.initials: S
authors.lastname: Licoccia
keywords: composite membranes; fuel cells; polymer electrolytes; proton transport; water sorption